Nichia and Sony have been working on the co-development of Blue-Violet laser diode for recording and playback on optical disc from June 2002. In April 2004, the cross license agreement in the concerned field has been successfully signed, leading to the mutual usage of the excellent patents owned by the two companies, targeting outstanding development of blue-violet related laser diodes.
Additionally, as part of the cross-licensing agreement set forth earlier in April of this year, the two companies will develop a lineup of laser-related devices, including blue-violet laser diode. Furthermore, Nichia and Sony plan to supply laser couplers to the market.

Comments from Mr. Gen-ichi Shinomiya, Managing Director, R&D, Engineering Headquarters, Optoelectronics Products Division, Nichia Corporation:
Nichia is a pioneer in the development of Galium Nitride-related lasers, being the first to introduce many such devices to the market. With the dual wavelength laser coupler in development, our target is to establish a formation for stable supply for the next generation optical storage field.

Comments from Dr. Osamu Kumagai, Microsystems Network Company, Sony's Device Solutions Company, Sony Corporation:
At Sony, based on the accomplishment of the mass production of the monolithic dual wavelength laser diode (announced in May, 2003), we have succeeded the development of the hybrid type of 3-wavelength blue-violet laser diode, as well as the optical head (announced in May, 2004). Furthermore, by selling Blu-ray related basic key devices, we are aggressively supporting Blu-ray Disc (BD) Standards.
In addition, by the dual wavelength laser coupler developed, this will enable ease in finished product development as well as realizing smaller size products, thus leading to new application development such as small-size BD players.

The dual wavelength laser coupler (prototype) is a single integrated device with a red laser (660 nm wavelength) for DVD playback and blue-violet laser (405 nm wavelength) for blue-violet optical disc playback. In conventional DVD/blue-violet laser optical disc systems, the laser diode and optical receiver parts corresponding to each wavelength were independent of each other. By introducing the newly developed dual wavelength laser coupler, the 2 functions can be incorporated in a single built-in element, realizing a simplified system, smaller size and enhanced reliability of the device.

<Fig. 1 : Comparison between main parts of conventional optical head and the dual wavelength laser coupler>